Biomaterial Database

Kinetics of aggregation of human platelets. 1978

A B Bikhazi, and G E Ayyub

A study of the aggregation kinetics of human platelets using an electronic counting device is reported. The experimental data were analyzed quantitatively by a physical model, which assumed that the initial disappearance rate of single platelets versus time fitted a second-order type of aggregation with respect to platelet number. The mechanism of aggregation was surface barrier controlled. Thus, the aggregation rate constants in different adenosine diphosphate concentrations (1.5-9.0 microgram) were 10-100 times greater than the rate constant (6.6325 x 10(-12) cm3/sec) for a diffusion-controlled mechanism, were smaller in the surface-barrier-controlled process and ranged from 0.00741 to 0.0467. The extent of aggregation was indicated by the calculation of a sticking probability constant as determined by the barrier. Adenosine diphosphate induced a rapid aggregating effect. Prostaglandin E1 produced the most drastic deaggregating effect as compared to dinoprostone (prostaglandin E2) and dinoprost (prostaglandin F2alpha). Aspirin completely blocked the aggregating effect of arachidonic acid.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010974	Platelet Aggregation	The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.	Aggregation, Platelet
D011458	Prostaglandins E	(11 alpha,13E,15S)-11,15-Dihydroxy-9-oxoprost-13-en-1-oic acid (PGE(1)); (5Z,11 alpha,13E,15S)-11,15-dihydroxy-9-oxoprosta-5,13-dien-1-oic acid (PGE(2)); and (5Z,11 alpha,13E,15S,17Z)-11,15-dihydroxy-9-oxoprosta-5,13,17-trien-1-oic acid (PGE(3)). Three of the six naturally occurring prostaglandins. They are considered primary in that no one is derived from another in living organisms. Originally isolated from sheep seminal fluid and vesicles, they are found in many organs and tissues and play a major role in mediating various physiological activities.	PGE
D011459	Prostaglandins E, Synthetic	Analogs or derivatives of prostaglandins E that do not occur naturally in the body. They do not include the product of the chemical synthesis of hormonal PGE.	PGE Synthetic,Prostaglandin E Analogs,Prostaglandin E Analogues,Synthetic Prostaglandins E,Analogs, Prostaglandin E,Analogues, Prostaglandin E,Synthetic, PGE
D011461	Prostaglandins F, Synthetic	Analogs or derivatives of prostaglandins F that do not occur naturally in the body. They do not include the product of the chemical synthesis of hormonal PGF.	PGF Synthetic,Prostaglandin F Analogs,Prostaglandin F Analogues,Synthetic Prostaglandins F,Analogs, Prostaglandin F,Analogues, Prostaglandin F,Synthetic, PGF
D006403	Hematologic Tests	Tests used in the analysis of the hemic system.	Blood Tests,Hematologic Test,Hematological Tests,Test, Hematologic,Tests, Hematologic,Blood Test,Hematological Test,Test, Blood,Test, Hematological,Tests, Blood,Tests, Hematological
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D001095	Arachidonic Acids		Eicosatetraenoic Acids,Acids, Arachidonic,Acids, Eicosatetraenoic